Tandem writing implement



Feb. 14, 1961 F. H. SEYER TANDEM WRITING IMPLEMENT Filed Oct. 3, 1955 IN V EN TOR.

Unite rates TANDEM WRITING IMPLEMENT Filed Oct. 3, 1955, Ser. No. 538,135

11 Claims. (Cl. 120-421) The present invention relates generally to writing implements. In particularly, the present invention relates to writing implements employing a tubular ink cartridge provided with a writing tip at one end and an open end at the other, with the cartridge so mounted in the implement that the writing tip is automatically retractable. Even more particularly, the present invention relates to a writing implement by which a plurality of ink cartridges may be connected in axial alignment within the implement in such a way that free communication of air with the open ends of the cartridges is provided at all times. While the present invention will be described as applied to a pen of the ball point type, it is not intended that its application be limited only to ball point pens as it will be obvious that the structure of the invention may be applied equally well to pencils, crayons or other types of marking devices.

conventionally, ball point writing instruments comprise a cylindrical barrel open at one end and containing an elongated tubular ink cartridge retractably mounted in the barrel so that the writing tip may be projected into a writing position. In writing with the instrument, the ball is caused to pick up ink from a supply carried in the cartridge and then. deposit or lay it down upon the surface over which the ball is rolled. Although ballpointed writing instruments of this type have been successfully used for many years, their use is not entirely free from difiiculty. For example, if the free universal rotation of the ball in the Writing tip is prevented for any reason, the pen will not write. This may occur if the ball is struck a sharp blow or dropped or otherwise caused to be jammed into a non-rotative position in its seat in the Writing tip. Thereafter, the pen is useless until the writing cartridge is replaced, much to the annoyance and inconvenience of the user.

Another difficulty arises because of the prevalent trend to prolong the useful life of such pens, primarily by the development of better inks and improved writing tips. However, the inexpensive materials advantageously employed in the construction of the tips frequently are unable to endure the longer periods of wear. Accordingly, the pen may cease to function altogether even though ink supply in the cartridge is far. from exhausted, the expected advantages being unrealized. Moreover, manufacturers of such pens are constantly faced with recurrent demands for instruments of varying length, or which will supply ink of different colors, or which provide writing tips with ball points of varying diameter. In the main, such demands have heretofore been ignored due to the difiiculty or impracticability of providing all such advantages in a single writing instrument.

Generally stated, the present invention provides means by which a plurality of tubular ink cartridges may be secured or connected in coaxial alignment within a writing implement so as to provide free access of air to the ink supply of at least one of the cartridges, the cartridges and connecting means forming an integral writing unit.

atcnt O ice Each cartridge is provided with a writing tip which may advantageously be constructed of less expensive materials as each of the tips 'will be required to deliver but a portion of the total ink supply. Moreover, the construction of the writing unit makes possible the use of inks of varying concentration or color in each of the cartridges, or the use of various size balls in the Writing tips. In an exemplary form of the invention, it is contemplated that the connecting means may also be independently employed as a device to protect the writing tip from damaging shocks or contacts with outside forces.

Accordingly one object of the invention. is to provide a'unitary device for use in a writing implement by which more than one writing tip is always available for use within the implement so that a damaged or inoperative writing tip will not render the entire device inoperative.

Another object of the invention is to provide an integral writing unit for use in such writing implements, said unit containing at least two writing tips which may vary in dimension or supply inks of different colors.

Another object of the invention is to provide means in a unitary writing device by which the wear of a ballpointed tip is reduced so that the likelihood that the device wiIl function throughout the life of the ink supply is substantially increased.

Another object of the invention is to provide a device for use in a writing implement by which a plurality of writing tips are made available for a given supply of writing fluid, permitting the use of less expensive materials in constructing the tips while providing an equal period of writing usefulness of the implement.

Other objects and advantages of the invention will be apparent from the following description and from the drawings, in which:

Fig. 1 is a view in section and in elevation of a writing implement embodying the invention;

Fig. 2 is an enlarged fragmentary view in section of the writing implement of Fig. 1, showing details of a means for connecting a plurality of ink cartridges in coaxial alignment;

Fig. 3 is a horizontal section along the line IIIIII of Fig. 2;

Fig. 4 is a horizontal section along the line IV-IV of Fig. 2; and

Fig. 5 is a view in elevation of the connecting device of Figs. 1 to 4, showing its use as a protective guard for a writing tip.

The writing implements illustrated in the drawings consist of a barrel or housing having a lower portion 10 provided with a downwardly directed port 12 adapted to receive the writing tip of a writing instrument and an upper barrel portion 14 which may include an outer shell 16 and an inner member or positioning element 13. The shell 16 may be fitted or cemented onto the positioning element, and the positioning element may be threadedly connected to the lower barrel portion as illustrated in Fig. 1.

Within the barrel or housing of the device, there is a writing unit 3 consisting of at least two tubular ink cartridges 29, 22, each provided with an open end 24 and a writing tip 26 terminating in a freely rotatable ball point 23. Between the ink cartridges, and connecting them securely into unitary coaxial alignment having a predetermined length, is a connector device adapted to provide air passages in communication with the open end of at least one of the ink cartridges. Each of the cartridges 20, 22 is provided with a crimped enlargement or stop 32 spaced from the writing tip so that a spring 34 may be trapped between the writing unit 8 and the lower or front end 36 of the barrel body. The spring normally urges the axially connected writing unit into a retracted position. A plunger 38 (adapted to cooperate 3 with" any suitable projecting or retracting mechanism) is provided to move the writing instrument from a retracted or non-writing position within the barrel to a projected or writing position externally of the barrel. As the details of the retracting mechanism do not form a part of this invention, they are not described or illustrated; However, suitable mechanisms for this purpose are fully described in United States Patent No. 2,624,314, issued to Walter B. Spatz, and copending application, Serial No. 374,497, filed August 17, 1953, by James L. Marcotte.

In a preferred embodiment of the invention, shown in Fig. 1, the writing instrument 8 comprises two cartridges held together in an axially telescoped relation, with the writing tip 26 of one cartridge positioned in the open end 24 of the other. Figs. 2 to illustrate a connector device 40 particularly adapted to this construction and showing the manner in which the axial connection may be readily facilitated. Preferably, the connector 40 is formed in one piece of a resilient plastic material such as an extruded, cast or molded polyethylene resin, although other resilient materials such as metals, resinous elastomers, composition materials and the like may be employed. In use, each cartridge is provided with a connector 40 firmly wedged in its upper end 24, providing an interchangeability of the cartridges in the writing unit 8, as will appear.

Referring to the illustrated apparatus, the connector 40 is formed substantially in the shape of an open-ended tube with one end 42 having an external configuration adapting it to pass freely into the open end of a tubular ink cartridge. The other end 44 of the connector is provided with an enlarged body portion 45 of approxirnately the same or substantially larger outside diamet er than the inside diameter of the open end 24 of the cartridge, terminating in a radially extending stop flange 48.- Stop flange 48 may be of preselected thickness for providing a predetermined length of the writing unit 8, said stop flange 48 having laterally extending oppositely directed seating faces for abutting engagement with faces on the associated cartridges being interconnected by the connector 40 and so that the writing unit 8 may effectively cooperate with a projection-retraction mechanism of an associated writing instrument.

The construction described permits the connector device 40 to be firmly wedged in the open end of a first tubular ink cartridge in position to receive the writing tip 26 of a second cartridge axially above the first. For the latter purpose, the lower end 42 of the connector has an internal configuration adapted to receiving the writing tip in wedged relation therein, and to providing ducts 50 about the tip for the passage of air. A particularly advantageous construction, typified in Fig. 4, utilizes an interior surface of substantially polygonal cross section, the shortest distance between any two sides 52 of the said interior surface being somewhat less than the diameter of the writing tip 26. For example, the square configuration shown in Fig. 4 provides four air ducts 50, one at each corner of the square, with the writing tip being resiliently held at circumferentially spaced zones by the side walls 52. As shown, the resilient sides 52 are expanded slightly outwardly by the larger diameter of the tip 26. The construction of the formed connector 40 thus provides circumferentially spaced and laterally extending zones provided in circumaxial relation to frictionally, resiliently grasp and hold the writing tip.

Although separate air passage means might be punched, milled or otherwise provided in the upper cartridge wall 24, it is a feature of the invention that the connector devices 40 provide uninterrupted air passages in communication with the upper surface 54 of the supply of ink or writing fluid in the ink cartridges 20 or 22. Accordingly, in the preferred embodiment of Figs. 1 to 5, the upper end 44 of the connector is provided with notched channels or recesses 56 extending radially outward from the center of the connecting device (Fig. 3),. The resulting air passages communicate freely with the interior of the connector device 40. To permit passage of air to the ducts 50 in the lower portion of the device, the internal configuration of the upper end 44 is such that air may freely pass about the shank 58 of the writing tip 26. For example, as illustrated in Fig. 3, a cylindrical interior surface, of a diameter somewhat larger than shank 58, may be provided.

From the above description, it will be apparent that the connector device 40 permits a single writing instrument to be assembled in axial relation from two separate ball-pointed cartridges, with the writing tip 26 of one cartridge firmly housed in the open end 24 of the other, both writing tips of the assembled unit then pointing in the same direction. As a result, two ball-pointed writing tips are always available, so that if one is dropped and damaged, or otherwise rendered inoperative, the pen may be disassembled and the positions of the cartridges reversed, presenting the undamaged point in writing position in the lower part of the barrel body. Irrespective which of the two cartridges so assembled has its writing ip in writing position, the other cartridge presents an upwardly directed open end for cooperation with a retracting mechanism such as the one operated by plunger 38, as previously stated. Moreover, if desired, the writing fluid in the separate cartridges may be of different concentration or color; or the dimensions of the ball points 28 may vary so that a writing instrument adapted to different uses may be provided. A further advantage resides in the fact that the writing tip may be fabricated of cheaper, less durable materials since two writing tips are available for the life of the ink supply instead ofthc usual one without any increase in the size or bulk of the barrel of the writing instrument. It will also be noted that the connector device at all times acts to protect the non-writing or housed tip from damaging impacts.

A further advantageous use of the connector device 40 might be as a protective guard for the separate writing tips during shipment or handling. In such case, the connector device would be employed independently of the writing instrument combination, for example, as shown in Fig. 5. There, the function of the connector device 4% is to serve as a resilient guard, protecting the delicate writing tip of a cartridge from any external impacts or contacts.

To those skilled in the art to which this in-ventionrelates, many additional changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. In combination with a structural writing unit comprising at least two ink cartridges each including a cartridge body with a writing tip at one end the provision of: means to interconnect the cartridges in a structurally rigid coaxial assembly adapted to be employed as an integral writing unit, said means comprising a hollow non-rigid resilient elongated member having a resilient cylindrical wall portion provided with longitudinally extending surfaces for gripping frictional engagement with a cartridge body and having another resilient wall portion providing an internal passageway with circumferentially spaced internal surfaces for gripping frictional engagement with a writing tip, received therewithin, said mem ber including at one end thereof a radially outwardly ex tending flange providing seating faces lying in spaced planes extending across the axis of the member to determine longitudinal relation of said cartridges.

2. The combination as stated in claim 1 wherein said radially outwardly directed flange is provided with an edge face disposed proximate to external surfaces of the cartridge bodies with which said flange is associated.

3. In combination with a structural writing unit comprising at least two ink cartridges, each including a cartridge body having an open end and carrying a writing tip at the opposite end, the provision of: a hollow resilient elongated member provided with a longitudinally extending surface frictionally engaging one cartridge body and provided with writing tip engagement surfaces, said resilient member including laterally extending means providing oppositely directed seating faces for determining longitudinal relation of said cartridges, said resilient member including an internal passageway including a portion of polygonal cross section receiving the writing tip of the other cartridge body, the walls defining said polygonal cross section providing said writing tip engagement surfaces.

4. A writing instrument comprising: a casing; a composite, structurally rigid writing unit assembly mounted therein for projection and retraction, said writing unit assembly including two tubular ink cartridges, each provided with a cartridge body having a writing tip at one end and having an opposite open end, said cartridges being disposed with the open end of one cartridge body receiving therewithin the writing tip of the other cartridge; connector means provided at the open end of one cartridge body frictionally grasping said writing tip of the other cartridge to hold said cartridges in rigid coaxial alignment and to provide structural integrity to the composite writing unit, said grasping means including circumferentially spaced frictional engagement zones adjacent said open end of said one cartridge body; and air passage means defined by said connector means at the open end of said one cartridge body communicating with the interior of said cartridge body, said air passage means including passageways lying between said spaced frictional engagement zones.

5. In combination with a structural writing unit comprising at least two ink cartridges, each including a cartridge body having an open end and carrying a writing tip having a shoulder adjacent the opposite end, the provision of: a hollow, resilient, elongated member provided with a longitudinally extending surface for frictional engagement with one cartridge body and provided with surfaces resiliently grasping said writing tip, said resilient member including laterally extending flange means providing oppositely directed seating faces engageable respectively with an edge face at the open end of said one cartridge body and with the shoulder of the writing tip of the other cartridge body for determining longitudinal relation of said cartridges.

6. The combination as stated in claim 5 wherein said resilient member is provided with air passage means at said flange means.

7. A structurally rigid writing unit for use in a writing instrument, said unit including a pair of tubular inkcontaining cartridges, each including a cartridge body and a reduced writing tip circular in section at one end of the body, each cartridge body having an open end portion, the provision of: means for interconnecting said cartridges comprising circumferentially spaced and laterally extending formed means provided in circumaxial relation at the open end portion of each cartridge body to internally, frictionally, resiliently grasp and hold a writing tip, circular in section, carried by the other cartridge.

8. A structurally rigid writing unit for use in a writing instrument, said unit including a pair of tubular inkcontaining cartridges, each including a cartridge body and a writing tip of reduced section at one end of the body, each cartridge body having an open end portion, the provision of: means for interconnecting said cartridges comprising circumferentially spaced and laterally extending formed means provided in circumaxial relation at the open end portion of each cartridge body to frictionally resiliently grasp and hold a writing tip carried by the other cartridge; and air passage means between said circumaxially related grasping means and defined by said formed interconnecting means providing a vent to the interior of the cartridge body radially outwardly of a writing tip grasped by said grasping means.

9. A structurally rigid writing unit for use in a writing instrument, said unit including a pair of tubular inkcontaining cartridges, each including a cartridge body and a ball type writing tip of reduced section at one end of the body, each cartridge body having an open end portion, the provision of: means for interconnecting said cartridges comprising circumferentially spaced and laterally extending formed means provided in circumaxial relation at the open end portion of one cartridge body to frictionally resiliently grasp and hold a writing tip carried by the other cartridge; said writing tip being provided with a shoulder of smaller diameter than the open end portion of said one cartridgebody, said circumaxially related grasping means defining therebetween air passageways to provide a vent in communication with the interior of the cartridge body, said formed means including seating surfaces engaging said shoulder.

10. A writing instrument comprising: a casing; a composite structurally rigid writing unit assembly mounted therein for projection and retraction, said writing unit assembly including two tubular ink-containing cartridges, each including a cartridge body and a ball type writing tip means, each cartridge body having an open end; and cartridge interconnecting means provided at the open end of one cartridge body frictionally resiliently grasping the writing tip means of the other cartridge body to hold said cartridges in rigid coaxial alignment and to provide structural integrity to the composite writing unit, said cartridge interconnecting means comprising circumferentially spaced, frictional engagement surfaces provided in circumaxial relation adjacent the open end portion of said one cartridge body and laterally extending means for engagement with the writing tip means on the other cartridge body.

11. In combination with a writing unit comprising at least two tubular ink cartridges, each including a cartridge body having a writing tip at one end and having an opposite open end, the provision of: connector means at the open end of one cartridge body frictionally grasping said writing tip of the other cartridge to hold said cartridges in rigid coaxial alignment and to provide integrity to the writing unit, said grasping means including circumferentially spaced frictional engagement zones adjacent said open end of said one cartridge body; and air passage means defined by said connector means at the open end of said one cartridge body communicating with the interior of said one cartridge body, said air passage means including circumferentially spaced passageways lying in close proximity to said spaced frictional engagement zones.

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